Most commercially available fluorinated surfactants are produced through electrochemical fluorination, telomerization, and oligomerization. Electrochemical fluorination utilizes anhydrous hydrofluoric acid as the fluorine source. However, industrially produced hydrofluoric acid contains impurities, which requires further complicated methods to remove these impurities.
Telomerization or oligomerization processes use tetrafluoroethylene as the starting material. However, the source of available tetrafluoroethylene is limited. The product obtained from telomerization process usually contains a mixture of homologues having different carbon chain lengths resulting in a distribution of carbon chain lengths. Therefore, the sequential separation of telomerization products is required in order to produce fluorosurfactants which contain a fixed length of the fluorinated carbon chain, as described by Erik Kissa in “Fluorinated Surfactants, Synthesis-Properties-Applications” Surfactant Science Series, Vol. 50, Marcel Dekker, New York, (1994).
U.S. Pat. No. 5,023,279 discloses the use of a special class of sulfonic and phosphonic acids, and salts of the acids to give improved nucleation for foam extrusion of thermoplastics to produce foam. The nucleating agent is of the formula [Z(CF2)x(CF2CFX)p(R′)y(CH2)zRO3]nM, wherein X is H, F, Cl, or CF3; M is a cation; R is sulfur or phosphorus; and R′ is a C5-C6 perfluorinated alicyclic ring diradical, a C1-C16 perfluorinated aliphatic polyether diradical with repeat units selected from [CF2O], [CF2CF2O], and [CF2CF(CF3)O], or a substituted or unsubstituted aromatic diradical, in which case, Z is H. The above nucleating compound is structurally different and is produced differently from the composition of the present invention.
It is desirable to have a composition comprising fluorinated surfactants which can be produced from starting materials other than tetrafluoroethylene. It is also desirable to have a method to lower surface tension using a very low concentration of surfactant and to provide surface effects. The present invention provides such a composition comprising fluorinated sulfonate surfactants which are produced from fluoroalkyl vinyl ether as the starting material for the fluorine source. The present invention also provides methods of providing various surface effects to liquids.